Each day a different image or photograph is featured, with an
accompanying caption, which deals with various topics in Earth Science.

Yarra Valley Rainbow Wheel

This breathtaking rainbow wheel was photographed from the Yarra Valley in Victoria, Australia, late in the day on March 25, 2008. Shadows in the sky (in this case caused by cumulonimbus clouds on the western horizon - not visible here) appear to converge towards the antisolar point because of the effects of perspective. This is also the direction we look to find rainbows. The bright spokes of the wheel are similar to anticrepuscular rays except that light is directed into specific directions by large raindrops rather than being widely scattered by dust and aerosol particles. Note that the spokes don't stop at the rainbow. On this early autumn day, the striking rays and colorful bow painted an unforgettable canvass.